The invention relates to apparatus for manipulating sheets, and more particularly to improvements in apparatus for singularizing stacked sheets of paper or the like. Still more particularly, the invention relates to improvements in singularizing apparatus of the type designed to remove successive sheets from a pile of superimposed sheets, for example, in a bookbinding, newspaper assembling or like machine.
German Auslegeschrift No 36 22 960 discloses a singularizing apparatus wherein a set of satellites is mounted for orbital movement along an endless path and each satellite has means for entraining a sheet during travel along a stack of superimposed sheets. If the apparatus of this reference is to singularize relatively large sheets, a number of satellites must be deactivated in order to enable the entraining means of the remaining (active) satellites to properly engage and transport such large sheets without any interference on the part of neighboring satellites. This ensures that successive sheets do not overlap during travel with the respective (active) satellites. A drawback of the just described singularizing apparatus is that its output decreases proportionally with the sizes of sheets which are to be singularized. Furthermore, the mechanism which is used to activate or deactivate selected satellites, depending on the sizes of sheets in a stack which is to be broken up into discrete sheets, is quite complex, expensive and prone to malfunction.